Dropout circuit interrupter



Jan. 13, 1942. s THOMPSON 2,269,611

DROPOUT CIRCUIT INTEPVRUPTER Filed Jan. 13, 1941 INVENTOR.

A 7'TORNEX Patented Jan. 13, 1942 DROPOUT CIRCUIT INTERRUPTER Joseph S. Thompson, Los Altos, Calif., assignor to Pacific Electric Manufacturing Corporation, San Francisco, Calif., a corporation of California Application January 13, 1941, Serial No. 374,151

9 Claims.

The present invention relates to high voltage circuit interrupters, and more particularly to a fusible circuit interrupter of the drop out type which, as is well understood, becomes disengaged from an upper contact and rotates into a suspended position from a lower contact where it remains until replaced.

An object of the invention is to provide an improved means by which dropout circuit interrupters of the above type may be replaced in a simple and convenient manner by means of a stick provided for this purpose.

Another object of the invention is to provide an improvement in dropout fusible circuit interrupters of the trunnion supported type which, in addition to facilitating a replacing of the interrupter upon its supporting contacts, will also operate to prevent an accidental displacement of the interrupter from its trunnion engaging support during the final replacing operation.

A further object of the invention is to provide a novel means by which dropout fuse units of the trunnion supported type may be conveniently placed upon their'trunnion engaging support in a simple and convenient manner and which will operate, when the dropout fuse unit is moved into its final operative position, to provide a good contact making engagement between the trunnions of the dropout fuse unit and the trunnion engaging terminal support.

Other objects and advantages of the invention will be in part evident to those skilled in the art and in part pointed out hereinafter in connection with the accompanying drawing, wherein there is shown by way of illustration and not of limitation several embodiments thereof.

In the drawing, wherein like numerals refer to like parts throughout the several views;

Figure 1 is a side elevation of a fusible dropout circuit interrupter embodying the present invention,

Figure 2 is an enlarged fragmentary view showing details of the invention as applied to the dropout unit of Figure 1,

Figures 3 and 4 are views similar to Figure 2 showing modified forms of the invention, and

Figures 5, 6 and '7 are detailed fragmentary views showing modified forms of an element of the invention.

For the purpose of illustrating the present invention there is shown in Figure 1 of the drawing a fusible dropout circuit interrupter of the type illustrated and described in my copending application Serial No. 320,807, filed February 26,

1940, and entitled Fusible circuit interrupter. As here shown, the fusible circuit interrupter, designated by the numeral i0, is adapted to be placed between suitable high voltage line terminals H and I2 that are carried by an insulator I3 which is adapted to be mounted upon a cross-arm or other suitable support H by means of a bracket l5. At its lower end the fusible dropout unit I0 is provided with a terminal or contact forming end l6 which has oppositely extending trunnions ii that are adapted to be cradled in recesses 18 formed in two spaced and extending portions l9 adjacent the lower line terminal contact ll. At its other end the fusible dropout unit It! is shown as having a latching contact 20, the details of which form the subject matter of my aforesaid copending application. When the fusible dropout unit i0 is in its operating position, the latching contact 20 will be held in contact making engagement with the line terminal [2 and thus a circuit will be established through the fusible dropout unit l0 between the line terminals H and 12.

These dropout circuit interrupters are primarily intended for use on high voltage circuits and they are, therefore, generally mounted in an elevated position upon a pole or tower where replacement is difiicult unless some special means is provided for this purpose. In the past, for replacing dropout fuse units of the trunnion supported type, it has been customary to provide a long insulating pole having a clamping Jaw at its end in which the body of the fuse is held while being placed in an operative position by a lineman at a safe distance therefrom. Another expedient has been to provide one or the other of the fuse terminals with an integral or rigidly formed eyelet into which an extension upon a suitable insulated pole may be placed to thus install the dropout unit. This latter expedient has found considerable favor because of its simplicity and inexpensive character, but it has been found that in some instances the provision of such an integrally formed eyelet upon the terminal end of the fusible dropout unit is not practical.

As is illustrated in Figure 1 of the drawing, the above difficulties have been overcome in the present invention by providing the lower or trunnion carrying end of the fusible dropout unit 10 with a bail 2| that is adapted to be engaged by an extending finger 22 carried by an insulating pole 23 in such a manner that the dropout unit ID will be held in a suspended position where its sequently applied to the body of the fuse unit through the pole 23, as is indicated by dot and dash lines in this figure of the drawing.

As is more clearly shown in Figure 2 of the drawing, thetrunnions ill upon the contact forming end It of the fusible dropout unit it are flattened or cut away on opposite sides in lines parallel to the axis of the fusible dropout unit ill, and the cradle forming recesses i8 are provided with an overhanging lip 26 so that a displacement of the trunnions ill from the cradle forming recesses it is prevented when the dropout unit I is rotated into its final operative position with respect to the upper line terminal l2 by means of the pole 23, as previously described.

In Figure 3 of the drawing there is shown an arrangement wherein the provision of the overhanging lip 24 upon the cradle forming recesses 98 and the flattening of the trunnions ill, as above described, is avoided. In this arrangement the bail 2i performs the additional function of preventing a displacement of the dropout fuse unit it from the cradle forming recesses it. As here shown, the trunnions, designated by the numeral 25, are cylindrical in outlin and the ball 2!, when released after an initial placingof the trunnions 25 in the cradle forming recesses it, takes a position of rest upon the cradle carrying a good electrical contact between the trunnions 25 and the extending portions it.

As shown in Figures 5, 6 and 7 of the drawing,

the bail and its mode of attachment to the trunnions ll of the fusible dropout unit it may take many forms. The arrangement illustrated in Figure 5 is considered to be the simplest and most inexpensive, as it only requires that the trunnions be provided with a bail receiving recess at their ends, either concentric or eccentric to their axes, into which inwardly bent ends of the ball 2! may be disposed. In Figure 6 there is shown a different form of bail 28 that may be stamped from sheet metal so as to provide eyelets 29 at the ends thereof which may be snapped over the trunnions. H of the dropout fuse unit l0, and in Figure 7 of the drawing there is shown a bail Bil having a substantially square configuraextensions I 9 in cooperating relation with'an abutment 26 that may be formed in any suitable manner upon one or both of the extending portions it of the lower terminal i i., With such an abutment 28, it will be seen that due to the inclined character of the cradle forming recesses l8 and the location of the abutment 2E substantially opposite thereto, the bail 2i will, when released, operate to prevent any displacement of the trunnions from the recesses 88 during a subsequent rotative movement of th dropout fuse unit ill into its final operative position by means of its placing stick.

In Figure 4 of the drawing there is shown a further variation of the invention in which a bail 2i of spring material, in addition to providing the above described functions, may also be relied upon to establish a good electrical contact between the trunnions 25 of the dropout fuse unit i0 and the extending portions l9 which carry the cradle forming recesses iii. In this latter arrangement, instead of the upwardly extending abutment 26, the extending portions it are shown as provided with suitably arranged notches 27 into which the outermost portion of the bail 2! is adapted to finally come to rest. The bail 2| is also here shown as secured in a position slightly eccentric to the axis of the extending trunnions 25. With this arrangement it will be seen that when the bail 2| is secured eccentric to the trunnions 25 in the manner illustrated, it will be placed under compression when the trunnions 25 of the fusible dropout unit iii are rotated counter-clockwise in the cradle forming recesses l8 and, as a result of its springing character, the bail 2i will exert a yielding pressure upon th trunnions 25 which will establish tion with eyelets 3i formed at its ends that are adapted to be disposed over-concentric or eccentrically arranged extensions 32 provided at the ends of the trunnions ll of the dropout fuse unit H3.

While I have, for the sake of clearness and in order to disclose the invention so that the same can be readily understood, described and illustrated specific devices and arrangements, I desire to have it understood that this invention is not limited to the specific means disclosed, but

may be embodied in other ways that will suggest themselves to persons skilled in the art. It is believed that this invention is new and all such changes as come within the scope of the appended claims are to be considered as part of this invention,

Having thus described my invention, what I claim and desire to secure by Letters Patent is: 1. The improvement in a cradle and trunnion supported fusible dropout circuit interrupting unit, which comprises the provision of a placing stick engaging bail pivotally secured at its ends to the trunnioned end of the dropout unit.

2. The improvement in a cradle and trunnion supported fusible dropout circuit interrupting unit, which comprises the provision of a placing stick engaging bail at the cradle supported end of the dropout unit, said bail being pivotally secured at its ends to the trunnions carried by the dropout unit.

3. In a dropout fuse unit of the character described, the combination of a cradle forming member, a fuse unit having oppositely extending trunnions adapted to engage said cradle forming member and form a pivotal support for said fuse unit, and a bail pivotally secured at its ends to said oppositely extending trunnions by which said fuse unit maybe placed upon said supporting member while suspended from a fuse unit replacing stick.

4. In a dropout fuse unit of the character described, the combination of a support having spaced cradle forming portions, a fuse unit having oppositely extending trunnions engageable with said spaced cradle forming portions to form a pivotal support for said fuse unit, a bail pivotally secured at its ends to said oppositely extending trunnions by which said fuse unit may be placed upon said supporting member while suspended from a replacing stick, and means upon said support engageable by said bail to prevent a displacement of said trunnions from said cradle forming portions when the fuse unit is in its operative position.

5. In a dropout fuse unit of the character described, the combination of a support having open cradle forming recesses, a fuse unit having oppositely extending trunnions adapted to drop into said cradle forming recesses and form a pivotal support for said fuse unit, a bail pivotally secured at its ends to said oppositely extending trunnions by which said fuse unit may be placed upon said supporting member while suspended thereby from a replacing stick, and an abutment upon said support disposed adjacent to said open cradle forming recesses and engageable by said ball for preventing a displacement of said trunnions from said open cradle forming recesses as the fuse unit is subsequently pivoted into its normal operating position by said placing stick.

6. In a dropout fuse unit of the character de scribed, the combination of a support having diagonally disposed open cradle forming recesses, a dropout fuse unit having oppositely extending trunnions adapted to drop into said cradle forming recesses and form a pivotal support at the lower end of said fuse unit, a bail pivotally secured at its ends slightly eccentric to the axis of said oppositely extending trunnions, and an abutment upon said support disposed in oppomd relation in said cradle forming recesses and engageable by said ball as said fuse unit is moved into its normal operating position, whereby said trunnions will be biased into contact making engagement with the recesses of said support as the fuse unit is rotated into its operative position.

7. A dropout fuse unit having cradle engaging trunnions extending from its lower terminal forming end, said trunnions having recesses formed in their outer ends, and a bail secured to said trunnions by bent ends disposed in the recesses of said trunnions.

8. A dropout fuse unit having cradle engaging trunnions extending from its lower terminal forming end, said trunnions having eccentrically disposed recesses formed in their outer ends, and

a bail secured eccentric to said trunnions by having its ends extended into the recesses of said trunnions.

9. A dropout fuse unit having cradle engaging trunnions extending from its lower terminal, said trunnions having reduced and projecting extensions, and a bail secured to said trunnions by eyelets formed at its ends and bent around the reduced and projecting extensions of said trunnions.

JOSEPH S. THOMPSON. 

